Available in: Redis Stack
Time complexity: O(1)
Returns number of required items (k), width, depth and decay values.
Array reply with information of the filter.
TOPK.INFO topk
1) k
2) (integer) 50
3) width
4) (integer) 2000
5) depth
6) (integer) 7
7) decay
8) "0.92500000000000004"